6781978368 has 648 divisors, whose sum is σ = 24045853104. Its totient is φ = 1897758720.

The previous prime is 6781978363. The next prime is 6781978369. The reversal of 6781978368 is 8638791876.

It is a tau number, because it is divible by the number of its divisors (648).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6781978363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 127961830 + ... + 127961882.

It is an arithmetic number, because the mean of its divisors is an integer number (37107798).

Almost surely, 2^6781978368 is an apocalyptic number.

6781978368 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6781978368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12022926552).

6781978368 is an abundant number, since it is smaller than the sum of its proper divisors (17263874736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6781978368 is a wasteful number, since it uses less digits than its factorization.

6781978368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 86 counting only the distinct ones).

The product of its digits is 24385536, while the sum is 63.

The square root of 6781978368 is about 82352.7678223386. The cubic root of 6781978368 is about 1892.8613348766.

The spelling of 6781978368 in words is "six billion, seven hundred eighty-one million, nine hundred seventy-eight thousand, three hundred sixty-eight".